Bottom Line:
From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced.Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted.This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally.

Affiliation: Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, United States of America.

ABSTRACTBetween November 2010, and May 2011, eleven cases of cholera, unrelated to a concurrent outbreak on the island of Hispaniola, were recorded, and the causative agent, Vibrio cholerae serogroup O75, was traced to oysters harvested from Apalachicola Bay, Florida. From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced. Genomic analysis demonstrated the presence of a suite of mobile elements previously shown to be involved in the disease process of cholera (ctxAB, VPI-1 and -2, and a VSP-II like variant) and a phylogenomic analysis showed the isolates to be sister taxa to toxigenic V. cholerae V51 serogroup O141, a clinical strain isolated 23 years earlier. Toxigenic V. cholerae O75 has been repeatedly isolated from clinical cases in the southeastern United States and toxigenic V. cholerae O141 isolates have been isolated globally from clinical cases over several decades. Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted. This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally.

Mentions:
The genomes of the eight V. cholerae FL Group isolates harbored Vibrio pathogenicity island 1 (VPI-1) encoding the toxin co-regulated pilus (TCP) shown to be responsible for biofilm formation in the intestine and a receptor for CTXΦ phage [36], [37]. VPI-1 of the V. cholerae FL Group is highly similar in structure to those of other clinical and environmental V. cholerae and V. mimicus (Figure 3). Interestingly, the tcpA gene (often used as a marker of V. cholerae biotype) of this group has the highest similarity with that of V. cholerae O395, a Classical biotype, while showing similarity of 77% with V. cholerae V51. However, a phylogeny of concatenated ORFs of this island demonstrates VPI-1 of the V. cholerae FL Group and V. cholerae V51 are closely related to each other from an evolutionary perspective, and significantly diverged from VPI-1 of other clinical and environmental V. cholerae and V. mimicus strains (Figure 4).

Mentions:
The genomes of the eight V. cholerae FL Group isolates harbored Vibrio pathogenicity island 1 (VPI-1) encoding the toxin co-regulated pilus (TCP) shown to be responsible for biofilm formation in the intestine and a receptor for CTXΦ phage [36], [37]. VPI-1 of the V. cholerae FL Group is highly similar in structure to those of other clinical and environmental V. cholerae and V. mimicus (Figure 3). Interestingly, the tcpA gene (often used as a marker of V. cholerae biotype) of this group has the highest similarity with that of V. cholerae O395, a Classical biotype, while showing similarity of 77% with V. cholerae V51. However, a phylogeny of concatenated ORFs of this island demonstrates VPI-1 of the V. cholerae FL Group and V. cholerae V51 are closely related to each other from an evolutionary perspective, and significantly diverged from VPI-1 of other clinical and environmental V. cholerae and V. mimicus strains (Figure 4).

Bottom Line:
From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced.Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted.This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally.

Affiliation:
Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, United States of America.

ABSTRACTBetween November 2010, and May 2011, eleven cases of cholera, unrelated to a concurrent outbreak on the island of Hispaniola, were recorded, and the causative agent, Vibrio cholerae serogroup O75, was traced to oysters harvested from Apalachicola Bay, Florida. From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced. Genomic analysis demonstrated the presence of a suite of mobile elements previously shown to be involved in the disease process of cholera (ctxAB, VPI-1 and -2, and a VSP-II like variant) and a phylogenomic analysis showed the isolates to be sister taxa to toxigenic V. cholerae V51 serogroup O141, a clinical strain isolated 23 years earlier. Toxigenic V. cholerae O75 has been repeatedly isolated from clinical cases in the southeastern United States and toxigenic V. cholerae O141 isolates have been isolated globally from clinical cases over several decades. Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted. This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally.